HOw to select only a part of an audio file of 1 channel only

Many years ago I used Steinberg Wavelab and I knew exactly what to do in order to choose only a part of a file on only one channel (left or right). Is it possible to do it with audacity? Basically I like to experiment, for ex. choose 3 seconds of the left channel only and amplify that part, those 3 seconds from that channel only, or only add reverb there or whatever.
The FAQ says, “How do I select audio in one track?” and this is not what I mean because in a stereo file it chooses both channels in doing so–left-click and drag.
Also are there markers on audacity? What I mean is to add a pointer at some point that you can visibly see to go back to later.
Thank you

OS: Windows 7 64 bit
Audacity ver. 2.0.4
downloaded as an exe (i think)

There’s a drop-down menu on the left of your tracks > Split Stereo Tracks. From then on, you can apply effects and filters to left or right – or both. When you’re done, you can marry left and right into one stereo track for exporting into a sound file.


Audacity doesn’t have Markers, but it does have Labels. You can set labels in a show and put text inside the label to remind you of what you intended. Exporting a sound file will not retain the labels, but Saving the show as an Audacity Project will.

Audacity Projects are not sound files and they only open in Audacity.